Mask

ABSTRACT

A mask includes a main body, mask cord and cord lock. The cord lock is made of an elastic material and movably attached to the mask cord for adjusting a circle contour formed by the main body, mask cord and cord lock for putting around a user&#39;s head. The cord lock includes a locking portion connected to a grip portion that internally defines a receiving space and the grip portion is divided into a deformable zone and a supporting zone. A smaller circle contour is adjustable to a larger one through deformation of the deformable zone, which allows the cord lock to move closer to the head and release some length of the mask cord that is originally received in the receiving space for expanding the circle contour. Meanwhile, the cord lock and the mask cord do not slide relative to each other and the mask maintains secure seal.

FIELD OF THE INVENTION

The present invention relates to a mask having cord locks attached tomask cords, and more particularly, to a mask having shape-deformablecord locks movably attached to mask cords.

BACKGROUND OF THE INVENTION

A mask for covering a user's nose and mouth is used to filter outairborne hazardous particles. Among others, N95 medical face mask forresisting pathogens is an indispensable item, particularly when thewhole world is suffering with the ongoing pandemic of corona virusdisease. Even though the N95 face mask has excellent filteringcapability, it is worn over a user's head to cover the face only viaelastic head loops, no matter what dimensions the user's head has. Toform a relatively large head loop, an elastic cord providing arelatively large tensile force is required. A mask having head loopsformed of elastic cords with large tensile force might cause discomfortto the user whose head is larger in dimensions.

To solve this problem, some masks available in the market arepurposefully produced to have longer head loop cords with a cord lockprovided on each of the cords. The cord lock divides the loop cord intoa loop section for fitting around the user's head to fix the mask to theuser's face, and a remaining section. The user may use the cord lock toadjust a length of the remaining section to thereby change the length ofthe loop section and accordingly, the size of the head loop, allowingthe head loop cord to exert a proper tensile force on the user's headfor snugly covering the mask over the user's face.

However, the user's face changes in shape, for example, when the usertalks, which renders the head loop cords into a repeatedly pulled orstretched condition. Under this circumstance, it is possible the cordlocks are brought to slide on and relative to the head loop cords tothereby increase the length of the loop sections and even result inloosened head loop cords, which will undesirably produce gaps betweenthe user's face and the mask.

SUMMARY OF THE INVENTION

A primary object of the present invention is to provide a mask with acord lock that is movably attached to a mask cord without thepossibility of undesired sliding relative to the mask cord. The cordlock is elastically deformable to avoid forming a gap between the maskand a user's face to preventing the user being exposed in dangerousenvironment.

Another object of the present invention is to provide a mask, of whicheach mask cord forms a size-adjustable loop section for wearing around auser's head. And, the mask has at least two adjustment mechanisms thatallow the loop section of the mask cord having been adjusted to acertain size to be quickly changed to another size at any time accordingto changes in a contour of the user's face or head.

A further object of the present invention is to provide a mask having aplurality of adjustment mechanisms that allow change in the size of aloop section formed by a mask cord and a main body without changing theposition of a cord lock relative to the mask cord while the mask canstill provide secure seal and comfortable attachment to a user's face.

A still further object of the present invention is to provide a maskhaving a mask cord formed into a loop section for putting around auser's head, and the loop section is adjustable in size by adjusting theposition of a cord lock relative to the mask cord. And the cord lock hasa shape designed for improving the way in which the cord lock contactswith the user's head, making the mask comfortable for wear.

To achieve the above and other objects, the mask according to anembodiment of the present invention includes a main body, a mask cordrespectively having two ends connected to the main body, and a cord lockattached to the mask cord. The mask cord and the cord lock together withthe main body form a circle contour for putting on a user's head to fixthe main body of the mask to the user's face. And, the cord lock is madeof an elastic material and movable relatively with the mask cord.

The cord lock includes a locking portion and a grip portion. The lockingportion is provided with a bore extended in a cord insertion direction;and the bore is elastically expandable by the mask cord, so that themask cord is clamped by the locking portion. The grip portion has anannular wall connected to the locking portion; the annular wallinternally defines a receiving space communicable with the bore of thelocking portion. And, the mask cord has a confined section including twobilaterally symmetrical parts, which are received in the bore and thereceiving space.

The annular wall of the grip portion includes a deformable zone and asupporting zone having a wall thickness larger than the wall thicknessof the deformable zone. The locking portion, the deformable zone and thesupporting zone are arranged in a straight line from bottom to topwithout overlapping one another in an initial state. The deformable zoneis bendable to form a first bent part and a second bent part when thecord lock is subjected to a force from a direction parallel to the cordinsertion direction; and the deformable zone is caused to overlap thelocking portion, such that the cord lock is changed from the initialstate into a invagination state. Wherein, when the cord lock is changedfrom the initial state into the invagination state, or changed from theinvagination state into the initial state, a size of the circle contouris changed.

In an embodiment, the receiving space has a cross-sectional area smallerthan or equal to the cross-sectional of the locking portion when thecord lock is in the initial state; and the deformable zone is subjectedto a push by the locking portion to deform when the cord lock is in theinvagination state, such that an original cross-sectional area of thedeformable zone is changed to an expanded cross-sectional area.

In another operable embodiment, the receiving space has across-sectional area larger than that of the locking portion when thecord lock is in the initial state; such that when the cord lock ischanged into the invagination state, the first bent part, the secondbent part and the locking portion directly enter into the receivingspace without changing the cross-sectional area of the receiving space,and the deformable zone is elongated when the supporting zone and thelocking portion move closer to each other.

In an embodiment, the deformable zone has an outer side forming aconical surface, the supporting zone has an outer side forming a roundsurface, and an inner wall surface of the deformable zone and an innerwall surface of the supporting zone together define a cylindrical innersurface. The locking portion is located adjacent to an end of thecylindrical inner surface, and the second bent part is located at an endof the conical surface to be adjacent to the round surface.

In an embodiment, the cord lock is movable relatively with the mask cordin the cord insertion direction when the cord lock is changed from theinitial state into the invagination state; and wherein the cord lock ismovable relatively with the mask cord in a direction opposite to thecord insertion direction when the cord lock maintains the initial state.

The cord lock further includes an abutting portion located at an end ofthe grip portion opposite to the locking portion and being formed withan annular flange, the abutting portion has an outer periphery largerthan that of the grip portion. The annular flange has an innerperipheral edge that is located adjacent to the receiving space and isformed into a rounded angle, and the annular flange defines a flatannular surface located perpendicular to the cord insertion directionand having an area larger than the cross-sectional area of the receivingspace.

In a preferred embodiment, the mask cord is made of an elastic materialand can generate a first deformation amount when being pulled; the cordlock can be moved on and relative to the mask cord to generate an amountof movement and the cord lock is compressible to generate a seconddeformation amount. The size of the circle contour is adjustable throughany one of the amount of movement, the first deformation amount and thesecond deformation amount.

In a preferred embodiment, the circle contour has a first sizedetermined by adjusting the amount of movement, and the first size ofthe circle contour is changeable to a second size larger than the firstsize through at least one of the first deformation amount and the seconddeformation amount.

In a preferred embodiment, when two forces are respectively applied tothe bilaterally symmetrical parts of the confined section in differentdirection, the locking portion can being deformed by the bilaterallysymmetrical parts; a first end of the bore located adjacent to thereceiving space is expanded when the bilaterally symmetrical parts areseparated to each other, and a second end of the bore far away from thereceiving space is narrowed by deformation of the locking portion.

In summary, the mask according to the present invention is characterizedin having a cord lock made of an elastic material. The cord lock ismovably attached to a mask cord, which forms a loop section for puttingaround a user's head, and includes a grip portion having a deformablezone and a locking portion connected to the deformable zone of the gripportion. When the cord lock is subjected to an external force appliedthereto, the deformable zone of the grip portion deforms to form a firstbent part and a second bent part. Therefore, the cord lock is changedfrom an initial state, in which the grip portion and the locking portionare not axially overlapped, into a invagination state, in which thelocking portion is moved closer to the grip portion to overlap the firstbent part and the second bent part. As a result, a confined section ofthe mask cord that is originally received in a receiving space of thegrip portion is released from the receiving space to thereby increase alength of the mask cord available for forming the loop section. Whenthere is a change in a peripheral length of the user's head, forexample, when the user is talking, and the loop section becomes tenser,the increased length of the loop section can release the tension toavoid the mask from loosening from the user's head due to sliding of thecord lock and the mask cord relative to each other. This design ensuresthe mask to provide a secure seal.

BRIEF DESCRIPTION OF THE DRAWINGS

The structure and the technical means adopted by the present inventionto achieve the above and other objects can be best understood byreferring to the following detailed description of the preferredembodiments and the accompanying drawings, wherein

FIG. 1 is a perspective view of a mask according to a first embodimentof the present invention;

FIG. 2 is a perspective view of a cord lock for each mask cord of themask shown in FIG. 1;

FIG. 3 is a sectional view of the cord lock shown in FIG. 2;

FIG. 4 is a sectional view showing the cord lock of FIG. 2 in use;

FIG. 5A is a plan view of the mask cord for the mask shown in FIG. 1;

FIG. 5B shows how the mark cord of FIG. 5A is partially compressed whenthe cord lock is attached thereto;

FIGS. 6A to 6F show the cord lock of FIG. 2 deforms when the mask cordextended therethrough is differently moved;

FIGS. 7a to 7D show the way of using the mask of the present inventionshown in FIG. 1; and

FIGS. 8A and 8B show a cord lock for a mask according to a secondembodiment of the present invention before use and after use,respectively.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described with some preferredembodiments and by referring to the accompanying drawings. For thepurpose of easy to understand, elements that are the same in thepreferred embodiments are denoted by the same reference numerals.

Please refer to FIG. 1 that shows a mask 10 according to a firstembodiment of the present invention. As shown, the mask 10 includes amain body 1 for filtering out pollutants, two mask cords 2 connected tothe main body 1, and two cord locks 3 separately attached to the twomask cords 2. The cord locks 3 are made of an elastic material and canbe moved relatively with the mask cords 2, and the mask cords 2respectively have two ends connected to the main body 1, such that themain body 1, the mask cords 2 and the cord locks 3 together define twocircle contours for wearing on a user's head 4 (shown in FIGS. 7A-7D) tofix the main body 1 to the user's face. As shown in FIG. 4, each of thetwo mask cords 2 can be divided into three generally bilaterallysymmetrical sections according to their position relative to the cordlock 3, namely, a loop section 21 located between the cord lock 3 andthe main body 1, a confined section 22 located in the cord lock 3, and aremaining section 23 located at another side of the cord lock 3 oppositeto the loop section 21. The confined section 22 is further divided intotwo sub-sections according to whether they are clamped by the cord lock3, namely, a reserved sub-section 221 located in but not clamped by thecord lock 3 and a clamped sub-section 222 located in and clamped by thecord lock 3.

In the first embodiment shown in FIG. 1, the main body 1 is a mask forcovering a user's mouth and nose. In other operable embodiments, themain body 1 can be otherwise a full-face respirator or a half-facerespirator that is currently available in the market.

In the illustrated first embodiment, the mask cords 2 respectively havetwo ends connected to the main body 1. However, in other operableembodiments, the mask cords 2 can be otherwise respectively have onlyone end connected to the main body 1 while the other end is a free end.In this case, the cord locks 3 can still be connected to a plurality ofmask cords 2 to form the circle contour between the main body 1 and thecord locks 3 for wearing on the user's head 4.

Since the two cord locks 3 are similar in structure, only one of them isdescribed hereinafter. Please refer to FIGS. 1 to 4. In the firstembodiment of the present invention, the entire cord lock 3 is made ofan elastic material and includes a locking portion 31, a grip portion 32and an abutting portion 33. The locking portion 31 is mainly used toattach to the mask cord 2. For this purpose, the cord lock 3 is providedwith a bore 311, and the mask cord 2 is inserted through the bore 311 ina direction, which is herein referred to as the cord insertion directionand denoted by reference numeral D1. The bore 311 has a first diameter31 a (see FIG. 3), which is elastically expandable into a seconddiameter 31 b (see FIG. 4) when the mark cord 2 is extended therethroughand exerts a force on the locking portion 31 of the cord lock 3. At thispoint, the clamped sub-section 222 of the mask cord 2 is clamped in thebore 311, and the cord lock 3 not subjected to an external force wouldnot easily slide on and relative to the mask cord 2 to undesirablychange its position on the mask cord 2.

The grip portion 32 has an annular wall connected to the locking portion31. The annular wall of the grip portion 32 includes a deformable zone321 and a supporting zone 322 thicker than the deformable zone 321. Thedeformable zone 321 is located between the supporting zone 322 and thelocking portion 31, and has a thickness gradually reduced in the cordinsertion direction D1, which gives the wall of the deformable zone 321a substantially triangular cross-sectional shape. Therefore, thedeformable zone 321 has an outer side forming a conical surface 321 a.The supporting zone 322 has a constant thickness in the cord insertiondirection D1, which gives the wall of the supporting zone 322 asubstantially rectangular cross-sectional shape. With this design, thesupporting zone 322 has an outer side forming a round surface 322 aconnected to the conical surface 321 a. Wherein, the thickness of thesupporting zone 322 and of the locking portion 31 are larger than thatof the deformable zone 321.

The grip portion 32 internally has a receiving space 232, which islocated adjacent to the locking portion 31 and communicable with thebore 311. The receiving space 323 is an open space defined by an innerwall surface of the supporting zone 322, an inner wall surface of thedeformable zone 321 and the bore 311. As shown in FIGS. 3 and 4, thereceiving space 323 is a substantially cylindrical structure extendedtoward one side of the locking portion 31 in the cord insertiondirection D1 and has a cylindrical inner surface 323 a formed by theinner wall surfaces of the supporting zone 322 and deformable zone 321.An end of the receiving space 323 opposite to the locking portion 31 isan opening 323 b, which is diametrically larger than the bore 311. Asshown in FIG. 4, when the mask cord 2 is extended through the cord lock3, the clamped sub-section 222 is clamped in the bore 311 while thereserved sub-section 221 is received in the receiving space 323.

Referring to FIG. 3 again. The abutting portion 33 is located at an endof the grip portion 32 opposite to the locking portion 31. Due to theelasticity provided by the elastic material of the cord lock 3, theabutting portion 33 is able to fitly contact with the user's head 4 (notshown in FIG. 3). In order to increase a contact area between the cordlocks 3 and the user's head 4, the abutting portion 33 is formed with anannular flange 324, which has an outer periphery larger than that of thegrip portion 32. The annular flange 323 defines a flat annular surface324 a located perpendicular to the cord insertion direction D1.Preferably, the flat annular surface 324 a has an area larger than across-sectional area of the opening 323 b, so as to increase the contactarea between the cord lock 3 and the user's head 4. The annular flange324 has an inner peripheral edge that is located adjacent to thereceiving space 323 and extended along the opening 323 b. It is notedthe inner peripheral edge of the annular flange 324 is formed into arounded angle 325.

From the above description of the cord lock 3, it can be seen that themask cord 2 and the cord lock 3 are held to each other when the clampedsub-section 222 of the mask cord 2 is compressed by the locking portion31. Therefore, as shown in FIG. 5A, the mask cord 2 selected for usewith the mask 10 is preferably formed of a plurality of elastic stripunits 251 extended in the same longitudinal direction and a limitingunit 252 for connecting the elastic strip units 251 to one another, suchthat the mask cord 2 has a substantially rectangular cross-sectionalshape.

The limiting unit 252 includes a plurality of connecting sections 252 aand a plurality of U-shaped turning sections 252 b. The connectingsections 252 a are extended in directions perpendicular to the elasticstrip units 251 to connect the latter to one another while any twoadjacent connecting sections 252 a are spaced from each other. Theturning sections 252 b are located at two opposite ends of theconnecting sections 252 a and each of the turning sections 252 b islocated between two adjacent connecting sections 252 a, such that thelimiting unit 252 extends in the same direction as the elastic stripunits 251 in a substantially zigzag pattern. With this design, it isable to limit a space between the elastic strip units 251 in thedirection perpendicular to the extending direction of the elastic stripunits 251.

As shown in FIG. 5B, when the mask cord 2 has a part compressed by thelocking portion 31 of the cord lock 3, the turning sections 252 b onother parts of the mask cord 2 that are not subjected to the compressionwould protrude from the outer side surface of the outermost elasticstrip unit 251 of the mask cord 2 to form a plurality of protrudedsections 253, which increase a frictional force between the lockingportion 31 and the mask cord 2.

The cord lock 3 will elastically deform in different degrees when themask cord 2 extended through the locking portion 31 is differentlypulled relative to the cord lock 3. Please refer to FIG. 6A. When it isdesired to move the cord lock 3 on and relative to the mask cord 2 in adirection opposite to the cord insertion direction D1, the user firstapplies a force on the annular flange 324 of the cord lock 3 in adirection opposite to the cord insertion direction D1, as indicated bythe two upward bold black arrows, and simultaneously applies a force onthe remaining section 23 of the mask cord 2 in the same direction as thecord insertion direction D1, as indicated by the downward bold blackarrow. This brings the mask cord 2 and the cord lock 3 to move in twoopposite directions, and allows the mask cord 2 to resist a forceexerted thereon by the bore 311 of the locking portion 31 and moverelative to the cord lock 3 in the cord insertion direction D1.

As can be seen in FIG. 6A, the deformable zone 321 of the cord mask 3does not deform because it is pulled in two opposite directions by thelocking portion 31 and the supporting zone 322 located at two oppositeends. Therefore, in the above process of moving the mask cord 2 relativeto the cord lock 3, the cord lock 3 keeps in an initial state S1, inwhich the deformable zone 321 is not bent. In the initial state S1, asshown in FIG. 6A, the abutting portion 33, the supporting zone 322, thedeformable zone 321 and the locking portion 31 are sequentially arrangedin a straight line along the cord insertion direction D1 withoutoverlapping one another.

Referring to FIG. 6B. When put the circle contour of the mask 10 overthe user's head 4, the cord lock 3 bears on the user's head 4 from anouter side of the mask cord 2. Due to the particularly shaped gripportion 32 and the locking portion 31, the remaining section 23 of themask cord 2 can be located at a position away from the user's head 4.

To facilitate easy description of a positional relation among the cordlock 3, the mask cord 2 and the user's head 4, the shape and thicknessof the cord lock 3 and the mask cord 2 shown in FIG. 6B all areillustrative. A person skilled in the art is supposed to know that,since the cord lock 3 is made of an elastic material, the mask cord 2has a thickness much smaller than that of the cord lock 3 and therefore,allows the cord lock 3 to contact with the user's head 4 through themask cord 2 when the user puts on the mask 10.

When the locking portion 31 of the cord lock 3 is subjected to a forceby pulling the mask cord 2 in a direction opposite to the cord insertiondirection D1, as indicated by the two black solid arrows in FIG. 6C, thelocking portion 31 will be pulled by the mask cord 2 to move toward thesupporting zone 322, as indicated by the white hollow arrow in FIG. 6C.In the above described process, when the supporting zone 322 and thelocking portion 31 are moved closer to each other, one side of thereceiving space 323 adjacent to the deformable zone 321 will expand dueto an elastic deformation of the deformable zone 321 to thereby have across-sectional area larger than that of the locking portion 31,allowing the locking portion 31 to move in a direction opposite to thecord insertion direction D1 and enter into an interior of the supportingzone 322. At this point, a length of the receiving space 323 in the cordinsertion direction D1 is shortened.

As shown in FIG. 6C, since the length of the receiving space 323 in thecord insertion direction D1 is shortened, a part of the confined section22 of the mask cord 2 that is initially located in the receiving space323 shall leave the receiving space 323 because the locking portion 31and the supporting zone 321 are moved closer to each other in theprocess of deformation of the cord lock 3.

In the moving process of the locking portion 31, since the receivingspace 323 has a cross-sectional area smaller than that of the lockingportion 31, the end of the deformable zone 321 located adjacent to thesupporting zone 322 forms a first bent part 321 b and another end of thedeformable zone 321 located adjacent to the locking portion 31 formed asecond bent part 321 c in the process of deformation. It is noted thefirst and the second bent part 321 b, 321 c are extended in differentdirections during the deformation process, causing the deformable zone321 to bend. Under this situation, the supporting zone 322 and thesecond bent part 321 c are subjected to a push by the first bent part321 b and the locking portion 31, respectively, to form a recessedgroove between the locking portion 31 and the deformable zone 321. Atthis point, the cord lock 3 is changed from the initial state S1, inwhich the locking portion 31, the supporting zone 322 and the deformablezone 321 are arranged in a straight line without overlapping oneanother, into a invagination state S2, in which the locking portion 31,the supporting zone 322 and the deformable zone 321 overlap one another.

In the illustrated first embodiment, due to the particularly designedshapes of the receiving space 323 and the deformable zone 321, aconnecting part of the grip portion 32 located between the deformablezone 321 and the locking portion 31 forms a thin-wall part 321 d, whichhas the thinnest wall thickness of the grip portion 32. The thin-wallpart 321 d is located close to an inner corner of the receiving space323, and its actual wall thickness is adjustable according to theelasticity of the mask cord 2, so that the thin-wall part 321 d isdeformed before the first and second bent parts 321 b, 321 c when thecord lock 3 is changed from the initial state S1 into the invaginationstate S2, and which can reduce the possibility of sliding of the maskcord 2 and the locking portion 31 relative to each other.

FIG. 6D is an enlarged view of the circled area A of FIG. 6C. Pleaserefer to FIGS. 6C and 6D at the same time. When the mask cord 2 issubjected to pull or stretch in a direction opposite to the cordinsertion direction D1 as shown in FIG. 6C, the two bilaterallysymmetrical parts of the reserved sub-section 221 initially located inthe receiving space 323 of the cord lock 3 will be pulled out of thereceiving space 323 and move farther away from each other, which in turnbrings the two bilaterally symmetrical parts of the clamped sub-section222 in the bore 311 to separate farther away from each other. Theseparating parts of the clamped sub-section of the mask cord 2 causes afirst end 311 a of the bore 311 of the locking portion 31 that islocated closer to the supporting zone 322 to elastically deform andthereby have an expanded cross-sectional area, as shown in FIG. 6D.Meanwhile, when the first end 311 a of the bore 311 of the elasticlocking portion 31 is expanded by the two separating bilaterallysymmetrical parts of the clamped sub-section 222, a second end 311 b ofthe bore 311 located farther away from the supporting zone 322 willbecome reduced in its cross-sectional area, also as shown in FIG. 6D, tothereby exert a stronger clamping force on the clamped sub-section 222of the mask cord 2.

Please refer to FIG. 6E. When the cord lock 3 in the invagination stateS2 is no longer subjected to the force applied thereto in the directionopposite to the cord insertion direction D1, the deformable zone 321,due to its elasticity, can automatically elastically restore from theexpanded state to its original shape, and the cord lock 3 is returned tothe initial state S1. Meanwhile, the locking portion 31 moves away fromthe supporting zone 322 again.

Please refer to FIG. 6F. When it is desired to move the cord lock 3along a large length of the mask cord 2 in the cord insertion directionD1, the user may apply a force on the annular flange 324 in the cordinsertion direction D1, as indicated by the two downward bold blackarrows in FIG. 6F, so that the cord lock 3 can resist the frictionalforce between the locking portion 31 and the mask cord 2 to move.

To avoid the bore 311 of the locking portion 31 from the deformationshown in FIG. 6D in the process of pulling the mask cord 2 in the cordinsertion direction D1, the user may pull the mask cord 2 for the twobilaterally symmetrical parts of the reserved sub-section 221 and of theclamped sub-section 222 to closely abut each other, as indicated by thehorizontal white hollow arrows in FIG. 6F, so that the mask cord 2 canbe more easily moved relative to the locking portion 31 withoutdeforming the bore 311.

Please refer to FIG. 7A. To use the mask 10, two circle contours formedby the main body 1, the mask cords 2 and the cord locks 3 are firstfitted around the user's head 4. In the event any one of the circlecontours has a size too large to match that of the user's head 4, theuser may adjust the position of the cord lock 3 on the mask cord 2 bymoving the cord lock 3 an amount relative to the mask cord 2 to therebychange a length of the loop section 21 of the mask cord 2 that forms thecircle contour, so that the size of the circle contour is reduced to afirst size 51 that matches the user's head size and is determinedaccording to the amount by which the cord lock 3 is moved on the maskcord 2, as shown in FIG. 7B. With the adjusted first size 51 of thecircle contour, the mask 10 covering the user's face can maintain asecure seal. The user may refer to FIGS. 6A to 6F for the detailedoperating procedures of adjusting the position of the cord lock 3 on themask cord 2.

Please refer to FIG. 7C. In the event an original contour of the user'shead 4 (as indicated by the dash line in FIG. 7C) is enlarged when theuser is talking, for example, and it is necessary to change the circlecontour of the first size 51 shown in FIG. 7B into a larger second size52, the circle contour can be adjusted to the larger second size 52 intwo ways. In the first way, the elasticity of the mask cord 2 allows forthe production of a first deformation amount on the mask cord 2 toelastically increase the length of the loop section 21. In the secondway, the cord lock 3 is elastically deformable to generate a seconddeformation amount on the shape of the cord lock 3 to thereby increasethe size of the circle contour. The above is more detailed described inthe following paragraphs.

Please refer to FIGS. 7B and 7C. When the contour of the user's head 4is enlarged, the mask cord 2 is subjected to pull or stretch and thelocking portion 31 of the cord lock 3 is brought to exert a force on theuser's head 4. At this point, the abutting portion 33 of the cord lock 3is tightly pressed against the user's head 4, and the cord lock 3 ischanged from the initial state S1 into the invagination state S2. In theprocess the cord lock 3 is changed from the initial state S1 into theinvagination state S2, the locking portion 31 will move closer to theuser's head 4, so that a part of the confined section 22 of the maskcord 2 that is originally received in the receiving space 323 will nowmove out of the receiving space 323 via the opening 323 b, which enablesthe original loop section 21 of the mask cord 2 to have an increasedlength to adapt to the enlarged contour of the user's head 4.

In the event the larger contour of the user's head 4 shown in FIG. 7C isreturned to the original contour shown in FIG. 7B, the originallydeformed cord lock 3 would automatically elastically recover to itsoriginal shape to thereby decrease the length of the mask cord 2 that isused to form the loop section 21. The user may refer to FIG. 6E for thedetailed operating procedures of adjusting the length of the loopsection 21.

Please refer to FIG. 7D. When the user wants to take off the mask 10 andneeds to largely increase the size of the circle contour, the user maymove the cord lock 3 along the mask cord 2 in the way described withreference to FIG. 6F to increase the length of the loop section 21.

In the process of increasing the size of the circle contour, the lockingportion 31 and the grip portion 32 would first move toward each other inresponse to the deformation of the deformable zone 321. And, due to themovement of the locking portion 31 toward the grip portion 32, the sizeof the circle contour can be increased without producing an amount ofmovement of the mask cord 2 relative to the cord lock 3. When the maskcord 2 is subjected to further pull or stretch, the mask cord 2 wouldslide relative to the locking portion 31 that is in the invaginationstate S2, i.e. the mask cord 2 would be pulled relative to the cord lock3 by an amount to thereby change the size of the circle contour. Then,the mask 10 can be easily taken off the user's face.

As having been mentioned above, since the locking portion 31 is formedof an elastic material, the bore 311 may be diametrically changed whenthe mask cord 2 is pulled or stretched relative to the cord lock 3.Therefore, when the user wants to increase the size of the circlecontour as shown in FIG. 7D, it is preferable for the user to firstlychange the cord lock 3 into the invagination state S2 with hand and thenfollow the steps described with reference to FIG. 6F to increase thesize of the circle contour, in order to avoid an increased frictionalforce between the locking portion 31 and the mask cord 2 due to thedeformation of the locking portion 31.

From the above description, it can be understood the cord lock 3 made ofan elastic material can partially deform when the mask cord 2 issubjected to an external force applied thereto and accordingly, bringsthe locking portion 31 connected to the mask cord 2 to move toward thesupporting zone 322 of the grip portion 32 via the deformation of thedeformable zone 321. The movement of the locking portion 31 toward thegrip portion 32 further enables releasing of a part of the confinedsection 22 of the mask cord 2 that is originally received in thereceiving space 323 of the cord lock 3 to thereby increase the length ofthe mask cord 2 that could be used to form the loop section 21. And, thesize of the circle contour can be changed by any one of the followingthree ways: (1) moving the cord lock 3 relative to the mask cord 2 by anamount; (2) using a first deformation amount produced by the mask cord 2due to an elasticity of its material; and (3) using a second deformationamount produced by the cord lock 3 when it is deformed.

According to the present invention, the cord lock 3 is not limited toany particular shape. Please refer to FIGS. 8A and 8B, which show a cordlock 3 for a mask 10 according to a second embodiment of the presentinvention. In the second embodiment, the cord lock 3 has a supportingzone 322 and a locking portion 31, both of which are substantiallybarrel-shaped and not easily deformable. The cord lock 3 in the secondembodiment further has a thin diaphragm located between the supportingzone 322 and the locking portion 31 to serve as the deformable zone 321.The supporting zone 322, the deformable zone 321 and the locking port 31together define the receiving space 323 that has a cross-sectional arealarger than that of the locking portion 31.

In the first embodiment, when the cord lock 3 is subjected to anexternal force applied thereto, the locking portion 31 and thesupporting zone 322 are moved closer to each other to thereby togetherexert a force on the deformable zone 321 and cause the latter to deform.Unlike the first embodiment, when the cord lock 3 for the mask 10 of thesecond embodiment is subjected to an external force applied thereto andbrings the locking portion 31 and the supporting zone 322 to move closerto each other, since the locking portion 31 has a cross-sectional areasmaller than that of the receiving space 323, the deformable zone 321 isdeformed only to elastically extends its length without causing anychange to the locking portion 31 and the supporting zone 322; and thedeformable zone 321 automatically elastically restores its originalshape when it is no long subjected to any force. In the secondembodiment, the first bent part 321 b is located at a joint between thedeformable zone 321 and the locking portion 31, and the second bent part321 c is located at a joint between the deformable zone 322 and thesupporting zone 322.

The present invention has been described with some preferred embodimentsand it is understood that many changes and modifications in thedescribed embodiments can be carried out without departing from thescope and the spirit of the invention that is intended to be limitedonly by the appended claims.

What is claimed is:
 1. A mask, comprising: a main body; a mask cordconnected to the main body; and a cord lock attached to the mask cord;the cord lock and the mask cord together with the main body forming acircle contour for putting on a user's head to fix the main body to theuser's face; and the cord lock being made of an elastic material to bemovable relatively with the mask cord; and the cord lock including: alocking portion provided with a bore extended in a cord insertiondirection; and the bore being elastically expandable by the mask cord,so that the mask cord is clamped by the locking portion; and a gripportion having an annular wall connected to the locking portion; theannular wall internally defining a receiving space communicable with thebore of the locking portion; and the mask cord having a confined sectionincluding two bilaterally symmetrical parts being received in the boreand the receiving space; the annular wall of the grip portion includinga deformable zone and a supporting zone having a wall thickness largerthan the wall thickness of the deformable zone; the locking portion, thedeformable zone and the supporting zone are arranged in a straight linefrom bottom to top without overlapping one another in an initial state;the deformable zone being bendable to form a first bent part and asecond bent part when the cord lock is subjected to a force from adirection parallel to the cord insertion direction; and the deformablezone is caused to overlap the locking portion, such that the cord lockis changed from the initial state into a invagination state; and whereinwhen the cord lock is changed from the initial state into theinvagination state, or changed from the invagination state into theinitial state, a size of the circle contour is changed accordingly. 2.The mask as claimed in claim 1, wherein the receiving space has across-sectional area smaller than or equal to the cross-sectional of thelocking portion when the cord lock is in the initial state; and thecross-sectional area of the receiving space being changed to an expandedcross-sectional area when the cord lock is in the invagination state andthe deformable zone is subjected to push by the locking portion todeform.
 3. The mask as claimed in claim 1, wherein the receiving spacehas a cross-sectional area larger than that of the locking portion whenthe cord lock is in the initial state; such that when the cord lock ischanged into the invagination state, the first bent part, the secondbent part and the locking portion directly enter into the receivingspace without changing the cross-sectional area of the receiving spaceand the deformable zone is elongated when the supporting zone and thelocking portion move closer to each other.
 4. The mask as claimed inclaim 1, wherein the deformable zone has an outer side forming a conicalsurface, the supporting zone has an outer side forming a round surface,and an inner wall surface of the deformable zone and an inner wallsurface of the supporting zone together define a cylindrical innersurface; the locking portion being located adjacent to an end of thecylindrical inner surface, and the second bent part being located at anend of the conical surface to be adjacent to the round surface.
 5. Themask as claimed in claim 1, wherein the cord lock is movable relativelywith the mask cord in the cord insertion direction when the cord lock ischanged from the initial state into the invagination state; and whereinthe cord lock is movable relatively with the mask cord in a directionopposite to the cord insertion direction when the cord lock maintainsthe initial state.
 6. The mask as claimed in claim 1, wherein the cordlock further includes an abutting portion located at an end of the gripportion opposite to the locking portion and being formed with an annularflange, the abutting portion has an outer periphery larger than that ofthe grip portion; the annular flange having an inner peripheral edgelocated adjacent to the receiving space and formed into a rounded angle,and defining a flat annular surface located perpendicular to the cordinsertion direction and having an area larger than the cross-sectionalarea of the receiving space.
 7. The mask as claimed in claim 1, whereinthe mask cord is made of an elastic material and can generate a firstdeformation amount when being pulled; the cord lock can be movedrelative to the mask cord to generate an amount of movement and the cordlock is compressible to generate a second deformation amount; and thesize of the circle contour is adjustable through any one of the amountof movement, the first deformation amount and the second deformationamount.
 8. The mask as claimed in claim 7, wherein the circle contourhas a first size determined by adjusting the amount of movement, and thefirst size of the circle contour being changeable to a second sizelarger than the first size through at least one of the first deformationamount and the second deformation amount.
 9. The mask as claimed inclaim 1, when two forces are respectively applied to the bilaterallysymmetrical parts of the confined section in different direction, thelocking portion can being deformed by the bilaterally symmetrical parts;a first end of the bore located adjacent to the receiving space isexpanded when the bilaterally symmetrical parts are separated to eachother, and a second end of the bore far away from the receiving space isnarrowed by deformation of the locking portion.